Oil and gas drilling and production operations involve the deployment of equipment down a borehole having considerable depth. Cost saving techniques include using steel tubing that is extended down the borehole or well casing and using the tubing to pump a variety of different fluids, including drilling mud and pressurized water. Typical equipment currently used to provide the continuous tubing includes a truck and trailer with a single coiled steel tube (also herein referred to as pipe) on a spool having an 8 to 10 foot inside diameter core that is wrapped with the tubing to provide a 14-foot outside diameter, where the spool is about 8 feet in length. However, this spool size and configuration, including current techniques and equipment limitations, prevent providing continuous coil tubing down the borehole or well casing at depths beyond approximately 9,500 feet for 2⅜ inch diameter tubing, or approximately 6,000 feet for 2⅞ inch diameter tubing, because the current equipment and spool configurations are too limiting.
FIG. 1 shows the typical current equipment layout for providing steel tubing down a borehole or well casing. Typically, an injector truck/trailer 10 is situated over a well W. The injector truck/trailer 10 typically includes equipment 12 and has a long edge 14 that is typically situated such that it is substantially parallel to the long edge 16 of a tubing supply truck/trailer 18. For the prior art shown in FIG. 1, the tubing supply truck/trailer 18 is shown to include a cab or truck 20 and a trailer 22. The injector truck/trailer 10 has a longitudinal axis LI—LI that is substantially parallel to a longitudinal axis LT—LT of the tubing supply truck/trailer 18. In addition, the longitudinal axis LI—LI of the injector truck/trailer 10 is oriented such that it is typically aligned with the longitudinal axis LT—LT of the tubing supply truck/trailer 18.
The tubing supply truck/trailer 18 includes a spool 24 of steel tubing T, where the spool 24 has flanges 26 to laterally confine and support the wound tubing T. The flanges 26 are typically oriented substantially parallel with the long edge 16 of the tubing supply truck/trailer 18. In addition, the spool 24 rotates about an axis A—A that is oriented substantially perpendicular to the long edge 16 of the tubing supply truck/trailer 18, as well as perpendicular to both the longitudinal axis LI—LI of the injector truck/trailer 10 and the longitudinal axis LT—LT of the tubing supply truck/trailer 18.
In use, as the tubing T is unwound, it is conveyed off the spool 24 and down the borehole or well W via the injector truck/trailer 10 and the equipment 12 that is located on the injector truck/trailer 10. However, as noted, this setup is substantially limiting in terms of the length of tubing that can be continuously fed down the borehole or well casing. Furthermore, this setup is also limiting because the tubing supply truck/trailer 18 has to be oriented substantially parallel to, and aligned with, the injector truck/trailer 10.
In view of the above, there is a long felt but unsolved need for equipment and methods that avoids the above-mentioned deficiencies and limitations of the prior art and that provides for greater lengths of continuous tubing to deep oil and gas boreholes and well casings.